The present invention relates in general to provide a pulley with a number of V-shaped grooves and a method of making this pulley.
The pulley with a number of V-shaped grooves is used for transmitting mechanical power and previously has been manufactured by cutting. Recently it has been proposed to manufacture this pulley by plastic processing or rolling (for example, Japanese Patent Kokai No. 188657/85 and Japanese Patent Kokai No. 88936/86), and the plastic processing or rolling is widely used today.
However, it is difficult for pulleys provided with a number of V-shaped grooves to obtain a sufficiently wide variety of desired shapes because of working condition difficulties, and the utilizable range of the pulley is limited because the cost of dies for making it and other costs are high. Pulleys made with a stepped shape by metal cutting are especially costly.